Hi,
I use code below to get the validator to work after the watermarkexterner.
protected void Page_Load(object sender, System.EventArgs e)
{
Page.ClientScript.RegisterStartupScript(this.GetType(), "rename", "<script type=\"text/javascript\">if (typeof(Page_ClientValidate_Org) == 'function')Page_ClientValidate_Org = Page_ClientValidate;delete Page_ClientValidate;</script>");
Page.ClientScript.RegisterStartupScript(this.GetType(), "create", "<script type=\"text/javascript\">function Page_ClientValidate(validationGroup){if (typeof(WebForm_OnSubmit) == 'function'){WebForm_OnSubmit();}if (typeof(Page_ClientValidate_Org) == 'function')return Page_ClientValidate_Org(validationGroup);else return true;}</script>");
}